Spiny starfish

Spiny starfish

Spiny starfish ©Linda Pitkin/2020VISION

Spiny starfish

Scientific name: Marthasterias glacialis
Our largest starfish, the Spiny starfish can reach an impressive diameter of 70cm!

Species information


Diameter: Normally up to 30cm
, can reach 70cm.

Conservation status


When to see

January to December


The Spiny starfish is unmistakeable - firstly, it is HUGE, growing to the size of a dustbin lid. Secondly, it really is very spiny - its whole body covered in white spines. It lives in shallow waters close to shore and down to depths of 200m. Spiny starfish are pale and normally pretty easy to spot on the seabed. Their skin is a pale grey-green and they often have beautiful purple tips to the end of their arms. Like other starfish, they too are a voracious predator and prey on bivalve molluscs, crustaceans and other starfish.

How to identify

The Spiny starfish is a pale greyish-green colour, sometimes with purple tips to its 5 arms. It is spiny - with each arm covered in three rows of spines. They can grow up to a huge 70cm across but most are smaller, with an average size of 30cm across. Smaller individuals can be confused with the Northern Starfish - a more northern species that lacks the white "wreath" like pedicellarie around the spines.


Most commonly recorded on the southwest coasts of England and Wales and west coast of Britain. It is also recorded at St Abbs on the East Coast.

Did you know?

When disturbed or stressed, this species will often shed one or more of its legs. Don't worry they will grow back! Spiny starfish are often spotted with 3 or 4 normal legs and 1 or 2 small legs in the process of regrowing.